Since Blasterforum is all about care, repair & modding and the Winter build/rebuild season is approaching, I thought this would be a good contest to give the leakdown tester some more exposure here. I'm sure most members already have one, 
so if the winner declines the prize it will be auctioned off to the highest bidder with the proceeds going to blasterforum.com.
This is an extra tester I made and is not a commercial unit. I made it outta all new stuff so it should serve someone just fine. The bulb will only pump to about 8 psi so it's safe for the gauge and your seals. The intake side fitting should fit stock & PJ34 carbs. Lotsa spigot sizes out there so you might have to mod to fit your boot. There are no guarantees, if it don't work for you then give it to someone who can make it work.
Contest runs for 1001 posts!
THE RULE! : Post as many times as you want but no more than 1 in 1 hour (if there is less than 60 minutes between any of your posts you are out). Excuses or misunderstanding won't save you. Just like using compressed air on the gauge, it will be damaged and excuses won't fix it!
Random number generator will pick a number between 2 & 1001.
I'm too lazy to write a how to so I stole this from 2strokeworld, props to the author!
-----------------------------------------------------------------------------------------------------------------
Leakdown test.
It's the only real way to find out where your airleaks might be w/o alot of hit and miss guesswork. First tighten things up to specifications (head bolts/intake bolts/spark plugs) You pump it up to 5~6psi. I remember reading somewhere, that if the leak is more than 2 psi over a 6 minute "sitting" period, you probably got a problem. If so, Take some windex, spray the head/base/intake gaskets & boot and even the tester itself to see if that is leaking (like i did)...if you see bubbles anywhere, that is where your leak is and you need to tighten things/replace/fix up in that area. If you don't see a leak, but it's still leaking 2 psi + over 6 minutes, you probably need to at least pull the points/generator off/ignition rotor and spray the left side crank seal, bubbles? that's a leak...no bubbles, no leak? Then drain the oil pull the right sidecover/clutch basket/primary gear and spray that sucker, i would guess, if the left side checked out okay.. You would probably know if a right side seal was gone (mine was ripped to shreds)...the smell would be like burning plastic and it would run terrible. A leak on the left side would cause a high idle or fluctuating idle and it would be near impossible to tune (jetting, good luck!). (I'd have a slightly high idle and then it would settle down, but i think my problem is in the carb itself (sticky slides or maybe when i tried to run castor oil and then didn't clean the carbs out?), since i can rule out leakdown not causing it).
It beats the hell out of guessing and lets you know exactly where the leak is. A fresh engine rebuild can leak, so many builders do a leakdown to prevent a problem from happening. I.E., they see the bubbles, tighten things up and retest until things are right. If it's a bad crank seal, then the engine can be taken apart (since it's already there on the bench) and better seals put in to fix, instead of having a seized motor return later with most probably an angry customer!!
-------------------------------------------------------------------------------
Big thanks to "slickerthanyou" for this leakdown vid. He uses a piece of rubber instead of a plug in the exhaust but the results are the same. If he hadn't done such a good job on the build we coulda seen some bubbles!
Only 1 of ya will win 1 so the rest that don't already have one should build one or better yet buy one like this bargain:
http://www.blasterforum.com/sale-18/leak-down-testers-28728/
Our friends living outside the U.S. might have to help me with shipping.
Good Luck, Have Fun & try to keep it clean ...Burp!
Oh, yah ... if you win and are a supporting member you'll also get 2 small ( 3" x 1/2" ) blasterforum supporting member stickers. Not as nice as freeks but still a sticker ... LOL .... no, you don't get the quarter!
so if the winner declines the prize it will be auctioned off to the highest bidder with the proceeds going to blasterforum.com.This is an extra tester I made and is not a commercial unit. I made it outta all new stuff so it should serve someone just fine. The bulb will only pump to about 8 psi so it's safe for the gauge and your seals. The intake side fitting should fit stock & PJ34 carbs. Lotsa spigot sizes out there so you might have to mod to fit your boot. There are no guarantees, if it don't work for you then give it to someone who can make it work.
Contest runs for 1001 posts!
THE RULE! : Post as many times as you want but no more than 1 in 1 hour (if there is less than 60 minutes between any of your posts you are out). Excuses or misunderstanding won't save you. Just like using compressed air on the gauge, it will be damaged and excuses won't fix it!
Random number generator will pick a number between 2 & 1001.
I'm too lazy to write a how to so I stole this from 2strokeworld, props to the author!
-----------------------------------------------------------------------------------------------------------------
Leakdown test.
It's the only real way to find out where your airleaks might be w/o alot of hit and miss guesswork. First tighten things up to specifications (head bolts/intake bolts/spark plugs) You pump it up to 5~6psi. I remember reading somewhere, that if the leak is more than 2 psi over a 6 minute "sitting" period, you probably got a problem. If so, Take some windex, spray the head/base/intake gaskets & boot and even the tester itself to see if that is leaking (like i did)...if you see bubbles anywhere, that is where your leak is and you need to tighten things/replace/fix up in that area. If you don't see a leak, but it's still leaking 2 psi + over 6 minutes, you probably need to at least pull the points/generator off/ignition rotor and spray the left side crank seal, bubbles? that's a leak...no bubbles, no leak? Then drain the oil pull the right sidecover/clutch basket/primary gear and spray that sucker, i would guess, if the left side checked out okay.. You would probably know if a right side seal was gone (mine was ripped to shreds)...the smell would be like burning plastic and it would run terrible. A leak on the left side would cause a high idle or fluctuating idle and it would be near impossible to tune (jetting, good luck!). (I'd have a slightly high idle and then it would settle down, but i think my problem is in the carb itself (sticky slides or maybe when i tried to run castor oil and then didn't clean the carbs out?), since i can rule out leakdown not causing it).
It beats the hell out of guessing and lets you know exactly where the leak is. A fresh engine rebuild can leak, so many builders do a leakdown to prevent a problem from happening. I.E., they see the bubbles, tighten things up and retest until things are right. If it's a bad crank seal, then the engine can be taken apart (since it's already there on the bench) and better seals put in to fix, instead of having a seized motor return later with most probably an angry customer!!
-------------------------------------------------------------------------------
Big thanks to "slickerthanyou" for this leakdown vid. He uses a piece of rubber instead of a plug in the exhaust but the results are the same. If he hadn't done such a good job on the build we coulda seen some bubbles!
http://www.blasterforum.com/sale-18/leak-down-testers-28728/
Our friends living outside the U.S. might have to help me with shipping.
Good Luck, Have Fun & try to keep it clean
...Burp!Oh, yah ... if you win and are a supporting member you'll also get 2 small ( 3" x 1/2" ) blasterforum supporting member stickers. Not as nice as freeks but still a sticker ... LOL .... no, you don't get the quarter!
Last edited by a moderator:
